Can digital breast tomosynthesis perform better than standard digital mammography work-up in breast cancer assessment clinic?

PURPOSE: To compare the efficacy of use of digital breast tomosynthesis (DBT) with standard digital mammography (DM) workup views in the breast cancer assessment clinic. MATERIALS AND METHODS: The Tomosynthesis Assessment Clinic trial (TACT), conducted between 16 October 2014 and 19 April 2016, is an ethics-approved, monocenter, multireader, multicase split-plot reading study. After written informed consent was obtained, 144 females (age > 40 years) who were recalled to the assessment clinic were recruited into TACT. These cases (48 cancers) were randomly allocated for blinded review of (1) DM workup and (2) DBT, both in conjunction with previous DM from the screening examination. Fifteen radiologists of varying experience levels in the Australia BreastScreen Program were included in this study, wherein each radiologist read 48 cases (16 cancers) in 3 non-overlapping blocks. Diagnostic accuracy was measured by means of sensitivity, specificity, and positive (PPV) and negative predictive values (NPV). The receiver-operating characteristic area under the curve (AUC) was calculated to determine radiologists' performances. RESULTS: Use of DBT (AUC = 0.927) led to improved performance of the radiologists (z = 2.62, p = 0.008) compared with mammography workup (AUC = 0.872). Similarly, the sensitivity, specificity, PPV, and NPV of DBT (0.93, 0.75, 0.64, 0.96) were higher than those of the workup (0.90, 0.56, 0.49, 0.92). Most radiologists (80%) performed better with DBT than standard workup. Cancerous lesions on DBT appeared more severe (U = 33,172, p = 0.02) and conspicuous (U = 24,207, p = 0.02). There was a significant reduction in the need for additional views (χ2 = 17.63, p < 0.001) and recommendations for ultrasound (χ2 = 8.56, p = 0.003) with DBT. CONCLUSIONS: DBT has the potential to increase diagnostic accuracy and simplify the assessment process in the breast cancer assessment clinic. KEY POINTS: • Use of DBT in the assessment clinic results in increased diagnostic accuracy. • Use of DBT in the assessment clinic improves performance of radiologists and also increases the confidence in their decisions. • DBT may reduce the need for additional views, ultrasound imaging, and biopsy.

The contribution of work-up or additional views to the accuracy of diagnostic mammography.

This study examines the influence of work-up on the accuracy of diagnostic mammography in symptomatic women. Subjects were sampled from all women consecutively attending a symptomatic breast clinic and aged 25-55 years (240 women shown to have breast cancer and 240 age-matched women shown not to have cancer). Mammography films were prospectively reported by two radiologists independently of each other and in a blinded manner using two phases of film reading: initially only baseline films were read, then mammography was re-read with work-up films. The accuracy of reporting mammography with and without work-up was compared using sensitivity and specificity, likelihood ratios, and receiver operating characteristic (ROC) curves. Reporting the mammogram with work-up (compared to without any work-up films) improved sensitivity (75.3% vs 69.0%, P=0.059) for one radiologist, with a non-significant gain in specificity (84.5% vs 79.4%, P=0.38). For the other radiologist, it resulted in a non-significant decrease in sensitivity (79.5% vs 83.7%, P=0.14) with a significant increase in specificity (85.6% vs 61.9%, P=0.00001). ROC curves for both radiologists showed that reporting mammography with work-up resulted in significant improvement (4.5% for R1, 6.8% for R2) in overall test accuracy. Our findings support the use of work-up mammography in the diagnostic setting.